Refrigeration apparatus for containers

Abstract

A container refrigeration apparatus includes: a casing which forms an external storage space communicating with the exterior of the container and an internal storage space communicating with the interior of the container; a refrigerant circuit; an external fan; an internal fan; and an inside air control system including an exhaust passage which allows a space on a blowout side of the internal fan in the internal storage space to communicate with the external storage space, and controls composition of the inside air in the container. An external end of the exhaust passage is open on a suction side of the external fan in the external storage space.

The invention claimed is: 
     
       1. A container refrigeration apparatus, comprising:
 a casing which is attached to an open end of a container for housing a respiring plant, and forms an external storage space communicating with the exterior of the container and an internal storage space communicating with the interior of the container; 
 a refrigerant circuit in which a condenser disposed in the external storage space and an evaporator disposed in the internal storage space are connected together to perform a refrigeration cycle; 
 an external fan which is disposed in the external storage space, and guides outside air into the external storage space to form a flow of the outside air toward the condenser; 
 an internal fan which is disposed in the internal storage space, and guides inside air in the container into the internal storage space to form a flow of the inside air toward the evaporator; and 
 an inside air control system controlling the composition of the inside air in the interior of the container, the inside air control system including
 a controller, 
 a gas supply device including at least one adsorption column provided with an absorbent adsorbing nitrogen in air, a first pump which supplies pressurized outside air to the at least one adsorption column, and a second pump which sucks the air from the at least one adsorption column and supplies nitrogen-enriched air having a higher nitrogen concentration than the outside air to the internal storage space, 
 an exhaust passage having an inlet end disposed on a blowout side of the internal fan in the internal storage space and an external end open on a suction side of the external fan in the external storage space, and 
 an exhaust valve that opens and closes the exhaust passage, wherein 
 the controller opens the exhaust valve during operation of the external fan such that the inside air flows from the internal storage space through the exhaust passage to the external storage space and outside the container even if the pressure in the interior of the container is lower than the pressure of the outside air. 
 
 
     
     
       2. The container refrigeration apparatus of  claim 1 , wherein
 the external storage space is divided by the condenser into a first space upstream of the condenser, and a second space downstream of the condenser in a direction of the flow of the outside air, 
 the external fan is disposed in the second space, 
 the second space is closed such that only a blowout port of the external fan is open toward the exterior of the container, and 
 the external end of the exhaust passage is open in the second space. 
 
     
     
       3. The container refrigeration apparatus of  claim 2 , wherein
 the exhaust passage is made of a tube which is inserted in a through hole formed through the casing to penetrate the casing, and 
 a draining structure is provided in an external portion of the tube extending in the external storage space, the draining structure including a trap which forms part of the tube and stores the condensed water, and a draining tube connected to the trap to guide the condensed water stored in the trap out of the container. 
 
     
     
       4. The container refrigeration apparatus of  claim 3 , wherein the draining structure is disposed in the external portion of the tube to be adjacent to the through hole. 
     
     
       5. The container refrigeration apparatus of  claim 3 , wherein part of the external portion of the tube downstream of the draining structure is disposed in the second space. 
     
     
       6. The container refrigeration apparatus of  claim 1 , wherein
 the external storage space is divided by the condenser into a first space upstream of the condenser, and a second space downstream of the condenser in a direction of the flow of the outside air, and 
 an external portion of the exhaust passage extending in the external storage space is at least partially disposed in the second space. 
 
     
     
       7. The container refrigeration apparatus of  claim 6 , wherein the external portion of the exhaust passage is entirely disposed in the second space. 
     
     
       8. The container refrigeration apparatus of  claim 6 , wherein
 the exhaust passage is made of a tube which is inserted in a through hole formed through the casing to penetrate the casing, and 
 a draining structure is provided in an external portion of the tube extending in the external storage space, the draining structure including a trap which forms part of the tube and stores the condensed water, and a draining tube connected to the trap to guide the condensed water stored in the trap out of the container. 
 
     
     
       9. The container refrigeration apparatus of  claim 8 , wherein the draining structure is disposed in the external portion of the tube to be adjacent to the through hole. 
     
     
       10. The container refrigeration apparatus of  claim 8 , wherein
 part of the external portion of the tube downstream of the draining structure is disposed in the second space. 
 
     
     
       11. The container refrigeration apparatus of  claim 1 , wherein
 the exhaust passage is made of a tube which is inserted in a through hole formed through the casing to penetrate the casing, and 
 a draining structure is provided in an external portion of the tube extending in the external storage space, the draining structure including a trap which forms part of the tube and stores the condensed water, and a draining tube connected to the trap to guide the condensed water stored in the trap out of the container. 
 
     
     
       12. The container refrigeration apparatus of  claim 11 , wherein the draining structure is disposed in the external portion of the tube to be adjacent to the through hole. 
     
     
       13. The container refrigeration apparatus of  claim 11 , wherein
 the external storage space is divided by the condenser into a first space upstream of the condenser, and a second space downstream of the condenser in a direction of the flow of the outside air, and 
 part of the external portion of the tube downstream of the draining structure is disposed in the second space.